1. Field of the Invention
This invention relates to an auto zoom camera and driving method therefor. More particularly, this invention relates to an automatic zoom camera and driving method therefor by which a user can take an optimal photograph by synthetically controlling a shading of a picture and a varying change of colour in response to a zoom operation in accordance with a distance of an object, sensitivity of a film, environmental brightness and a brightness index of a strobe.
2. Description of the Prior Art
In order to make operation easy, generally middle class and low class cameras are made as automatic cameras with electronic circuits, such as a distance detecting means for automatically controlling the focus of a lens, a brightness detecting means and a shutter driving means for automatically controlling the exposure of film, a motor driving means for automatically controlling the transfer of the film and the movement of a lens group, a flash driving means for automatically compensating for a lack of sufficient light.
These automatic cameras have also been enhanced by mounting a zooming apparatus on the camera which is responsive to the request of a user. This allows the user to obtain have various visual angles while remaining still and to convert into a wide-angle lens or a telephoto lens by varying a focus distance of the lens.
As is known, the zooming apparatus of an ordinary automatic camera generally utilizes a lens block which can be moved back and forth within a body tube in order to provide for a wide-angle position and a telescopic position. However, this type of zooming apparatus has a disadvantage in that the user cannot obtain a photograph of a good quality due to changes of the colour and the shading of the picture when the user carries out the zoom function.
Korea Utility Model Publication No. 92-7904, filed on Dec. 18, 1992, and entitled with "Diaphragm Control Circuit in Response to Zoom Operation of a Video Camera", discloses a control circuit which can adequately control a diaphragm in response to a zoom operation of the camera to improve the abovementioned disadvantage of the changes of the colour and the shading of the image in case of zooming.
However, there is still a disadvantage in that the above-mentioned control circuit can not synthetically control the changes of the colour and the shading of the photograph during a zoom operation since this control circuit simply controls an exposure value by closing the diaphragm little by little as the zoom operation moves to a wide stage, namely, zooms out, and opening the diaphragm little by little as the zoom operation moves to a tele stage, namely, zooms in.
Also, there is an inconvenience in that the zooming apparatus of an automatic camera including the above-mentioned control circuit can not automatically set the zoom function.